PURPOSE Apolipoprotein B mRNA editing enzyme catalytic polypeptide-like 3B (APOBEC3B) is a recently discovered protein that is considered important in causing mutations in tumor cell genome bases. Whether APOBEC3B is expressed in nasopharyngeal carcinoma (NPC) still remains unknown. Studies have shown that programmed-cell-death receptor-1 ligand (PD-L1) is highly expressed in NPC, but its clinical significance has not been fully elucidated. We aimed to evaluate APOBEC3B and PD-L1 protein expression in NPC and also investigate their prognostic significance. MATERIALS AND METHODS One hundred and three patients with NPC were retrospectively collected in this study, and were followed-up for 5 years. The expression of APOBEC3B and PD-L1/PD-1 in NPC was detected by immunohistochemical staining. RESULTS High expression of APOBEC3B was observed in 42.7% of NPC patients. The high expression rate of APOBEC3B was 31.5% in patients without recurrence or metastasis within 5 years, and 55.1% in those patients with recurrence or metastasis, and the difference was statistically significant (P=0.016). There was no significant difference in APOBEC3B expression among patients with different sex, age group, and clinical stage (P>0.05). The positive expression rate of PD-L1 was 55.3% in all patients with NPC. There was no significant difference in PD-L1 expression among patients with different sex, age group, clinical stage, and tumor recurrence or metastasis condition (P> 0.05). There was no significant correlation between the expression of APOBEC3B and PD-L1 in NPC patients. The positive expression rate of PD-1 was 1.9% (2/103) in patients with NPC. CONCLUSIONS APOBEC3B showed association with aggressive behavior and poor outcome in NPC, and is also considered as a potential marker for predicting NPC recurrence or metastasis. PD-L1 is not associated with the aggressive behavior and poor outcome in NPC.

中文翻译：

---

APOBEC3B和PD-L1/PD-1在鼻咽癌中的预后意义

目的载脂蛋白 B mRNA 编辑酶催化多肽样 3B (APOBEC3B) 是最近发现的蛋白质，被认为在导致肿瘤细胞基因组碱基突变方面很重要。APOBEC3B 是否在鼻咽癌 (NPC) 中表达仍然未知。研究表明，程序性细胞死亡受体-1配体（PD-L1）在鼻咽癌中高表达，但其临床意义尚未完全阐明。我们旨在评估 NPC 中 APOBEC3B 和 PD-L1 蛋白的表达，并研究它们的预后意义。材料与方法 本研究回顾性收集鼻咽癌患者103例，随访5年。免疫组化染色检测APOBEC3B和PD-L1/PD-1在NPC中的表达。结果 在 42 人中观察到 APOBEC3B 的高表达。7%的鼻咽癌患者。APOBEC3B的高表达率在5年内未复发或转移的患者中为31.5%，在复发或转移的患者中为55.1%，差异有统计学意义（P=0.016）。APOBEC3B 表达在不同性别、年龄组和临床分期患者之间无显着差异（P>0.05）。PD-L1在所有鼻咽癌患者中的阳性表达率为55.3%。不同性别、年龄组、临床分期、肿瘤复发或转移情况的患者PD-L1表达差异无统计学意义（P>0.05）。APOBEC3B与PD-L1在鼻咽癌患者中的表达无显着相关性。鼻咽癌患者PD-1的阳性表达率为1.9%（2/103）。结论 APOBEC3B 与 NPC 的攻击行为和不良预后相关，也被认为是预测 NPC 复发或转移的潜在标志物。PD-L1 与 NPC 的攻击行为和不良预后无关。